Riding lawn mowers are so convenient to use. Because they have larger engines with wider mowing decks, they cut lawns more quickly than the equivalent push or self-propelled lawnmowers are capable of. A riding lawnmower is an excellent investment if you have a large property with a sizeable yard.

You can jump-start most riding lawnmowers with a car if you follow basic precautions and the car’s electrical system is in good order. A vehicle will have enough power to jump-start the riding lawnmower if you sufficiently prepare both the jumper leads and the batteries.

If riding lawnmowers break down, they are much harder to move around and transport to a lawnmower technician; this means that lawnmower owners should become familiar with the bits that make the lawnmower work and carry out minor repairs. (Check out post how much does riding lawnmower weight.)

A flat battery falls into the category, and you should efficiently resolve this problem.

How Do You Safely Jump Start A Lawnmower?

If the lawnmower’s starter motor does not turn over fast enough when you turn the ignition key on, or if there is a clicking sound, the lawnmower’s battery may not have enough charge, and the lawnmower won’t start.

There are three possible solutions to correct the situation which are.

Solution 1 –   Attach The Battery To A Charger

If you are willing to postpone mowing the lawn, a battery charger is the best solution.

Battery chargers are more efficient than a lawnmower’s charging system.

Most riding lawn mowers use an alternator to charge the battery. Most battery chargers generally have a better performance than a riding lawnmowers alternator because they usually have a ‘refresh’ mode which ensures optimum performance and life.

The higher the amps the battery charger produces the “deeper” the charge and the quicker the battery charges.

You have two options if you need the lawnmower to be started immediately.

Solution 2 – Attach A Battery Pack

A stand-alone battery pack offers some advantages compared to jumping your riding lawnmower from a car.

Battery packs are portable devices that hold sufficient charge to start a lawnmower with a flat battery.

They weigh very little and can supply up to 900 amps to enable a recalcitrant battery to start the riding lawnmower.

They offer the following benefits.

They Are Safer For The Electrical System

Most portable battery packs have a polarity protection feature.

If the user crosses the polarity (connects the positive terminal to the negative and vis-versa ), the battery pack will warn the user and cut the connection until the cables are changed over.

Connecting the leads backward can cause significant damage to both the car and lawnmower electrical systems.

Battery Packs Are Safer For Users

While jumper cable clamps tend to spark, battery packs don’t deliver power until a proper connection is established.

By eliminating sparks, there is a lower possibility of an explosion of the hydrogen gas, which may have leaked from the lead-acid battery.

You Can Use Battery Packs For More Than One Purpose

In addition to the jump-starting capability, many battery packs also come equipped with DC power sockets, USB charging sockets, air compressors, or emergency lighting.

More expensive units include an inverter and convert the current to run devices that need AC.

Solution 3 – Jumping The Riding Lawnmower From A Car

If there is no battery pack available and both the lawnmower and the motor vehicle electrical systems are rated at 12 volts, you can use a car to jump start the riding lawnmower.

Follow the steps listed below to jump the lawnmower from the car safely.

Step 1 – Access The Riding Lawnmower Battery

Open or lift the hood, which covers the riding lawnmowers battery. In many instances, this is situated under the operator’s seat.

If the battery terminals are corroded, 1) disconnect the riding lawnmower cables; 2) Mix a spoon of baking soda into a cup of tepid water; 3) Use the mixture to scrub off all the corrosion.

Check the battery voltage is 12 volts and not 6 volts. If the riding lawnmower is a very old model, the battery voltage could be 6 volts. In this instance, you cant jump the lawnmower battery from the car.

Step 2 – Connect Both Batteries

Connect the positive (red) cable to the corresponding terminal on the car’s battery. It is essential that you FIRST connect the positive lead to both batteries.

The positive cable has red insulation or a red battery clamp and may be marked with the word “POS” or have a plus (+)  sign.

Connect this cable to the corresponding terminal on the riding lawnmower’s battery.

It doesn’t matter whether you connect the car’s battery or the lawnmower battery first.

After you connect the positive cable to both batteries, connect one end of the negative wire to the remaining terminal of the car’s battery.

The negative cable has black insulation or a black battery clamp and may be marked with a “NEG” or a minus (-) sign.

Connect the negative cable to a shiny clean metal surface on the lawnmower. If possible, don’t connect the negative cable directly to the negative terminal on the battery, as it may spark, igniting hydrogen gas that could be leaking.

Step 3 – Start The Lawnmowers Engine

Try to start the lawnmower’s engine.

If the car’s battery has an insufficient charge to start the lawnmower, try starting the car’s engine first.

The car’s charging system will generate more power, and the lawnmower may run on a second try.

If successful, let it run for two minutes and then disconnect the jumper cables in the reverse order to how you connected them.

Why Did The Battery Go Flat?

Although by now you may have started the lawnmower and are happily cutting the lawn, it is worthwhile trying to find out the reason the riding lawnmower battery lost its charge in the first place.

The following are some common reasons a lawnmower battery may lose its charge.

There Is A Problem With The Lawnmowers Charging System

Check that the alternator is in good working order and all the components appear in good condition.

Lawnmowers are designed to be operated at full power. The alternator will only produce sufficient charge if the engine speed is adequate.

Even a 10% reduction in engine speed will prevent charging the battery. If you suspect the engine is not producing sufficient revs, arrange for it to be serviced.

The Battery Is In Bad Condition

Batteries age and, over time, need to be replaced. If your battery takes more than eight hours to charge with a battery charger, it is probably damaged and needs to be replaced.

The Batteries Terminals Have Corroded

The presence of corrosion doesn’t automatically mean that the battery needs to be replaced, but if corrosion is evident, you should find out the reason.

If the battery cables are not tightly fastened, a more significant load is imposed on the battery, which will cause it to drain more quickly.

The Riding Lawnmowers Electrical System Is Discharging The Battery

Check all the lawnmowers wiring for breaks in the insulation. The battery may be discharged because a short circuit is caused by damaged wiring.

Check the electrical consumers (lights, horns, etc.) do not have damaged circuitry or switches that are not disconnecting the circuits.


If your riding lawn mower battery is not sufficiently charged to start the engine, it is possible to use your car’s battery to jump-start the lawnmower engine.

Ideally, it is more efficient and safer first to charge the lawnmower battery or use a battery pack to start the mower.

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